U.S. patent application number 14/030968 was filed with the patent office on 2014-01-16 for calibration of a chemical dispense system.
This patent application is currently assigned to Intermolecular, Inc.. The applicant listed for this patent is Intermolecular, Inc.. Invention is credited to Rajesh Kelekar.
Application Number | 20140014681 14/030968 |
Document ID | / |
Family ID | 49355109 |
Filed Date | 2014-01-16 |
United States Patent
Application |
20140014681 |
Kind Code |
A1 |
Kelekar; Rajesh |
January 16, 2014 |
Calibration of a Chemical Dispense System
Abstract
In one implementation, a method for providing a fluid at a
target pressure may include providing a fluid at a velocity to a
supply line through a dispenser, measuring a pressure of the fluid
flowing through the supply line, comparing the measured pressure
with the target pressure, and adjusting the velocity based on the
results of the comparison.
Inventors: |
Kelekar; Rajesh; (Los Altos,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Intermolecular, Inc. |
San Jose |
CA |
US |
|
|
Assignee: |
Intermolecular, Inc.
San Jose
CA
|
Family ID: |
49355109 |
Appl. No.: |
14/030968 |
Filed: |
September 18, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12239555 |
Sep 26, 2008 |
8561627 |
|
|
14030968 |
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Current U.S.
Class: |
222/1 |
Current CPC
Class: |
H01L 21/67017 20130101;
B67D 7/085 20130101; Y10T 137/0379 20150401; Y10T 137/7761
20150401; Y10T 137/85986 20150401; Y10T 137/86002 20150401; F04B
49/065 20130101; Y10T 137/0396 20150401 |
Class at
Publication: |
222/1 |
International
Class: |
B67D 7/08 20060101
B67D007/08 |
Goverment Interests
GOVERNMENT RIGHTS IN THIS INVENTION
[0002] This invention was made with U.S. government support under
contract number H94003-07-C-0712. The U.S. government has certain
rights in this invention.
Claims
1. A method of dispensing a specified volume of a fluid into a
destination vessel, the method comprising: determining a flow rate
in a supply line corresponding to a target pressure; calculating an
amount of time required to dispense the specified volume of the
fluid at the flow rate; and dispensing the fluid at the target
pressure through the supply line to the destination vessel for the
amount of time.
2. The method of claim 1, wherein determining the flow rate that
corresponds to the target pressure comprises: retrieving
calibration data on a plurality of pressures and corresponding flow
rates for a dispense path coupled to the destination vessel; and
calculating a flow rate corresponding to the target pressure from
the calibration data.
3. The method of claim 2, wherein the dispense path is coupled
directly to the supply line.
4. The method of claim 2, wherein the dispense path is coupled to
the supply line through a supply manifold.
5. The method of claim 2, further comprising: opening a valve to
allow fluid flow through the dispense path; and closing the valve
after the amount of time expires.
6. The method of claim 5, wherein the valve is a multi-way
valve.
7. The method of claim 5, wherein the valve is opened and closed by
a controller.
8. The method of claim 2, wherein the calibration data is generated
by a process comprising: pushing a plunger in a dispenser to
dispense a fluid into the supply line; measuring a resulting
pressure in the supply line; computing a corresponding flow rate
from a volume of the fluid dispensed into the supply line and the
time elapsed in dispensing the fluid; and recording the resulting
pressure and the corresponding flow rate.
9. The method of claim 8, wherein the plunger is pushed by a
motor.
10. The method of claim 8, wherein the plunger is pushed at a
constant velocity.
11. The method of claim 8, wherein the plunger is pushed with a
constant acceleration.
12. The method of claim 1, wherein the dispensing of the fluid
volume comprises setting a pressure regulator to the target
pressure; wherein the pressure regulator is coupled to a supply
vessel containing a dispensed fluid; and wherein the supply vessel
is coupled to the supply line.
13. The method of claim 12, wherein the pressure regulator provides
a pressurized gas to the supply vessel at a regulated pressure; and
wherein the pressurized gas pushes fluid out of the supply vessel
into the supply line.
14. The method of claim 12, further comprising: measuring a
pressure at the supply line; comparing the measured pressure with
the target pressure; and adjusting the pressure regulator based on
the comparison.
15. The method of claim 12, further comprising using a controller
to adjust the regulated pressure from the pressure regulator.
16. The method of claim 1, further comprising: defining multiple
regions of a substrate; and processing the multiple regions of the
substrate in a combinatorial manner; wherein processing the
multiple regions comprises varying the target pressure of the fluid
across the multiple regions.
17. The method of claim 16, wherein varying the target pressure
comprises consistently applying the fluid across the multiple
regions.
18. The method of claim 16, wherein processing the multiple regions
comprises varying the volume of the fluid across the multiple
regions.
19. The method of claim 18, wherein varying the volume comprises
consistently applying the fluid across the multiple regions.
20. The method of claim 16, further comprising: characterizing the
multiple regions; and determining which of the multiple regions
meet criteria for subsequent processing or evaluation.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional claiming priority to U.S.
patent application Ser. No. 12/239,555, filed 26 Sep. 2008, which
is entirely incorporated by reference herein for all purposes.
BACKGROUND
[0003] 1. Field of the Invention
[0004] Implementations of various technologies described herein
generally relate to substrate processing.
[0005] 2. Description of the Related Art
[0006] The following descriptions and examples do not constitute an
admission as prior art by virtue of their inclusion within this
section.
[0007] To achieve the desired performance enhancement for each
successive generation of silicon integrated circuits (ICs),
semiconductor manufacturing has become increasingly reliant on new
materials and their integration into advanced process sequences.
Unfortunately, typical semiconductor manufacturing equipment is not
well suited for materials exploration and integration. Issues
impacting the use of typical semiconductor manufacturing equipment
include difficulty in changing process materials and chemicals
rapidly, limited ability to integrate and sequence multiple
materials or chemicals in a single reactor or process chamber, high
equipment cost, large sample size (e.g. 300 mm wafers) and
inflexible process/reactor configurations. To complement
traditional manufacturing tools, a need has arisen for process
equipment that facilitates fast testing of new materials and
materials processing sequences over a wide range of process
conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Implementations of various technologies will hereafter be
described with reference to the accompanying drawings. It should be
understood, however, that the accompanying drawings illustrate only
the various implementations described herein and are not meant to
limit the scope of various technologies described herein.
[0009] FIG. 1A illustrates a schematic diagram for implementing
combinatorial processing in connection with implementations of
various technologies described herein.
[0010] FIG. 1B illustrates an exemplary substrate containing
multiple regions for combinatorial processing according to
implementations of various technologies described herein.
[0011] FIG. 2 illustrates a combinatorial processing tool in which
various technologies may be incorporated and used in accordance
with various techniques described herein.
[0012] FIG. 3 illustrates a schematic diagram of a combinatorial
processing tool according to implementations of various techniques
described herein.
[0013] FIG. 4 illustrates a flow diagram of a method for
calibrating a chemical dispense system according to implementations
of various techniques described herein.
[0014] FIG. 5 illustrates a flow diagram of a method for providing
a chemical dispense system with a predetermined volume of a fluid
according to implementations of various techniques described
herein.
[0015] FIG. 6 illustrates a flow diagram of a method for providing
a fluid to a chemical dispense system at a predetermined pressure
according to implementations of various techniques described
herein.
DETAILED DESCRIPTION
[0016] The following paragraphs provide a brief general description
of one or more implementations of various technologies and
techniques directed at calibrating a fluid flow rate with respect
to a pressure in a chemical dispense system that may be part of a
combinatorial processing tool. In one implementation, the fluid may
be a liquid chemical used in the combinatorial processing tool. A
dispenser, such as a syringe, containing the fluid may be coupled
to a supply line of the chemical dispense system. The supply line
may be coupled to a supply manifold having a plurality of valves.
Each valve may be coupled to a dispense path, which may be used to
provide the fluid a path to one or more vessels and/or one or more
reactors within the combinatorial processing tool. A pressure
indicator may be coupled to the supply line to measure the pressure
available at the supply line.
[0017] A controller may be coupled to a motor, which may be
configured to push a plunger of the dispenser. In one
implementation, the motor may push the plunger at a constant
velocity or at a velocity with a constant acceleration such that
the fluid contained within the dispenser may be provided to the
supply line with a constant flow rate or a flow rate with a
constant acceleration. The resulting pressure at the supply line
may then be measured by the pressure indicator. Given the volume of
fluid dispensed into the supply line by the dispenser and the time
elapsed in providing the volume of fluid, the controller may
determine the flow rate of the fluid provided to the supply line.
The flow rate of the fluid may then be recorded along with a
corresponding pressure value obtained from the pressure indicator.
The resulting fluid flow rate and pressure data may then be used as
calibration data that may correlate a fluid flow rate to its
pressure value.
[0018] In another implementation, the controller may use the
calibration data that correlates a fluid's flow rate to its
pressure value to provide a specified volume of a fluid into a
destination vessel. The controller may first receive inputs from a
user specifying a target pressure and a specific volume of the
fluid to be provided to the destination vessel. The controller may
then determine the fluid flow rate that corresponds with the fluid
and the specified target pressure from the calibration data of the
chemical dispensing system. Using the fluid flow rate, the
controller may calculate an amount of time required to fill the
destination vessel with the specified volume of the fluid at the
target pressure. The controller may then allow the fluid to flow to
the destination vessel at the target pressure for the calculated
amount of time. The resulting volume of fluid in the destination
vessel may be equal to the volume originally specified by the
user.
[0019] In yet another implementation, the controller may also be
used to provide a fluid to the supply line at a specified pressure.
After receiving a specific pressure value from a user, the
controller may send a command to the motor to push the plunger at a
constant velocity. A pressure indicator may be used to measure the
corresponding pressure of the fluid being provided into the supply
line. The controller may receive the corresponding pressure value
from the pressure indicator, and it may compare this received
pressure value with the pressure value specified by the user. Based
on the results of the comparison, the controller may increase or
decrease the velocity in which the motor pushes the plunger in the
dispenser in order to provide the fluid at the user's specified
pressure value.
[0020] The various implementations in calibrating a chemical
dispense system with a dispenser may have advantages in that they
may ensure that a chemical may be delivered to one or more vessels
or reactors in a combinatorial process tool at a specified flow
rate, volume, or pressure. The ability to specify the flow rate,
volume, or pressure may increase the accuracy in which a chemical
reaction takes place for a combinatorial process. Furthermore, the
use of a dispenser may eliminate the need for a flow meter, which
may consequently reduce the complexity and costs while increasing
the accuracy of the combinatorial processing tool. The dispenser
may be used to accurately dispense a small amount of a chemical
while measuring the flow rate of the chemical which may also be
useful for combinatorial processing. The dispenser may also be used
to determine the flow rate properties or calibration data of the
chemical dispense system and its various dispense paths. The
calibration data may improve the consistency and repeatability of
the combinatorial process by accurately measuring the flow rate for
each dispense path connected to a vessel or a reactor.
[0021] One or more implementations of various techniques for
calibrating a chemical dispense system with a dispenser will now be
described in more detail with reference to FIGS. 1-5 in the
following paragraphs.
[0022] The discussion below is directed to certain implementations.
It is to be understood that the discussion below is only for the
purpose of enabling a person with ordinary skill in the art to make
and use any subject matter defined now or later by the patent
"claims" found in any issued patent herein.
[0023] Combinatorial processing may include any processing,
including semiconductor processing, which varies the processing
conditions across one or more substrates. As used herein, a
substrate may be, for example, a semiconductor wafer, a portion of
a semiconductor wafer, solar photovoltaic circuitry, or other
semiconductor substrate. The term "substrate" includes a coupon,
which is a diced portion of a wafer, or any other device on which
semiconductor processes are performed. The coupon or substrate may
optionally contain one die, multiple dice (connected or not through
the scribe), or portion of die with useable test structures. In
some implementations, multiple coupons, or die can be diced from a
single wafer and processed combinatorially.
[0024] Combinatorial processing is performed by varying processing
conditions across multiple substrates, multiple regions of a single
substrate, or a combination of the two. Processing conditions may
include, for example, chemical formulation, fluid flow rates,
temperatures, reaction times, concentrations, agitation or
stirring, and the like. For example, a first region of a substrate
may be processed using a first process condition (e.g., applying a
chemical at a first temperature) and a second region of the
substrate may be processed using a second process condition (e.g.,
applying the chemical at a second temperature). The results (e.g.,
the measured characteristics of the processed regions) are
evaluated, and none, one, or both of the process conditions may be
selected as suitable candidates for larger scale processing (e.g.,
further combinatorial processing or deposition on a full
wafer).
[0025] Several combinatorial processing tools can be used. One type
of tool may include a reactor block that has several openings
(e.g., cylindrical openings) that define individual reactors on one
or more substrates. Each of the openings may further include a
sleeve that creates a seal with the substrate to contain processing
fluids or chemicals within a single reactor (i.e.,
"site-isolated"). For example, a reactor block may include 28
openings that define 28 regions on a substrate. Each of the 28
regions can be processed using varying process conditions, or
multiple regions can have the same processing conditions. For
example, seven sets of processing conditions can be performed
across four regions each. Each region can then be characterized
using various techniques (e.g., electrical test, microscopy), and
useful or beneficial techniques and/or conditions can be
selected.
[0026] Other combinatorial processing may be performed in a manner
that is not site isolated. For example, a wafer can be divided into
many small coupons, each of which can be processed using different
conditions. Using another example, a wafer can be processed using a
gradient approach, where the processing varies over the substrate.
These techniques may also be used in combination with site-isolated
combinatorial techniques.
[0027] FIG. 1A illustrates a schematic diagram 100 for implementing
combinatorial processing in connection with implementations of one
or more technologies described herein. The schematic diagram 100
illustrates that the relative number of combinatorial processes
that run with a group of substrates decreases as certain materials
and/or processes are selected. Generally, combinatorial processing
includes performing a large number of processes during a first
screen, selecting promising candidates from those processes,
performing the selected processing during a second screen,
selecting promising candidates from the second screen, and so on.
In addition, feedback from later stages to earlier stages can be
used to refine the success criteria and provide better screening
results.
[0028] For example, thousands of materials are evaluated during a
materials discovery stage 102. Materials discovery stage 102 is
also known as a primary screening stage performed using primary
screening techniques. Primary screening techniques may include
dividing wafers into coupons and depositing materials using varied
processes. The materials are then evaluated, and promising
candidates are advanced to the secondary screen, i.e., materials
and process development stage 104. Evaluation of the materials may
be performed using metrology tools such as electronic testers and
imaging tools, e.g., microscopes.
[0029] The materials and process development stage 104 may evaluate
hundreds of materials (i.e., a magnitude smaller than the primary
stage) and may focus on the processes used to deposit or develop
those materials. Promising materials and processes are again
selected, and advanced to the tertiary screen or process
integration stage 106, where tens of materials and/or processes and
combinations are evaluated. The tertiary screen or process
integration stage 106 may focus on integrating the selected
processes and materials with other processes and materials.
[0030] The most promising materials and processes from the tertiary
screen are advanced to device qualification stage 108. In device
qualification, the materials and processes selected are evaluated
for high volume manufacturing, which normally is conducted on full
wafers within production tools, but need not be conducted in such a
manner. The results are evaluated to determine the efficacy of the
selected materials and processes. If successful, the use of the
screened materials and processes can proceed to the manufacturing
stage 110.
[0031] The schematic diagram 100 is an example of various
techniques that may be used to evaluate and select materials and
processes for the development of semiconductor devices. The
descriptions of primary, secondary, etc. screening and the various
stages 102-110 are arbitrary and the stages may overlap, occur out
of sequence, be described and be performed in many other ways.
[0032] FIG. 1B illustrates a substrate 120 having multiple regions
for combinatorial processing in accordance with various techniques
described herein. Substrate 120 includes several regions 122 on
which semiconductor processes can be performed. For example, the
regions 122a, 122b, and 122c may each have an electroless layer
deposited on them. The region 122a may use a first chemical
formulation, the region 122b may use a second chemical formulation,
and the region 122c may use a third chemical formulation. The
resulting layers can be compared to determine the relative efficacy
of each of the formulations. None, one, or more of the formulations
can then be selected to use with further combinatorial processing
or larger scale processing (e.g., manufacturing). Any process
variable (e.g., time, composition, temperature) or process
sequencing can be varied using combinatorial processing.
[0033] As discussed above, each of the regions 122 may or may not
be site isolated. Site isolation refers to a condition where the
regions 122 can be processed individually and independently without
interference from neighboring regions. For example, one or more of
the regions 122 may include a sleeve having an end that forms a
fluid seal with the substrate 120. The sleeve is configured to
contain processing fluids (e.g., chemicals), and is made from a
material (e.g. polytetrafluoroethylene (PTFE)) that does not react
with the processing chemicals used. The chemicals do not leak out
of the region into which they were dispensed, and each region 122
can be processed and evaluated individually.
[0034] Each of the regions 122 may be processed using a cell of a
combinatorial processing tool, as described in FIG. 2. The tool is
calibrated so that processing in each of the regions 122 is
consistent and comparable. Using techniques described herein,
pressure within the combinatorial processing tool may be monitored
and the pressure supplied to the chemical supply vessel or bottle
can be adjusted so that the flow rate in the flow cells stays
consistent and calibrated. With these techniques, processed regions
across one or multiple substrates may show reliable results that
can be compared and characterized when performing combinatorial
processing. For example, some of the implementations described
herein can help provide consistent fluid delivery across multiple
regions of a substrate. These embodiments can improve combinatorial
processing by improving repeatability and comparability of certain
processing techniques.
Combinatorial Processing Tool
[0035] FIG. 2 illustrates a combinatorial processing tool 200 in
which one or more implementations of various technologies described
herein may be incorporated and used. Although various
implementations described herein are with reference to the
combinatorial processing tool 200, it should be understood that
some implementations may use other types of combinatorial
processing tool, such as a combinatorial processing tool with an
open deck or any other type of combinatorial processing tool that
uses stirring.
[0036] The combinatorial processing tool 200 may include a reactor
block 206 having a plurality of reactor cells 208. The reactor
block 206 is configured to mate with a stage or chuck 204, which is
configured to secure a substrate 215. The combinatorial processing
tool 200 may also include a floating reactor sleeve or wall 210,
which may be configured to float or be dynamically positionable in
each reactor cell 208.
[0037] FIG. 3 illustrates a schematic diagram of a combinatorial
processing tool 300 according to implementations of one or more
technologies described herein. The combinatorial processing tool
300 illustrated in FIG. 3 may be a wet processing tool and may be a
portion of a larger combinatorial processing tool. Portions of the
combinatorial processing tool 300 may be replicated several times
within a larger combinatorial processing tool such that a larger
number of variations in substrate processing conditions may be
achieved.
[0038] The combinatorial processing tool 300 illustrated in FIG. 3
may be divided into three parts. A chemical supply portion 302 may
supply chemicals to a chemical mixing portion 304 and a site
isolated reactor portion 306. The chemical mixing portion 304 may
be used for mixing various chemicals, e.g., liquid chemicals, into
solutions which may be applied to various locations on a substrate
in the reactor portion 306. In one implementation, the chemical
mixing portion 304 may be removed from the combinatorial processing
tool 300. The reactor portion 306 may contain a site isolated
reactor and may apply the solutions to the substrate or portions of
the substrate and may subject the substrate or portions thereof to
various processing conditions. The reactor portion 306 may be
coupled to a waste portion 308 of the combinatorial processing tool
300. The waste portion 308 may be used to capture waste chemicals
which were not used during substrate processing.
[0039] The supply portion 302 of the combinatorial processing tool
300 may include a supply vessel 310 containing a liquid chemical.
The chemical may be applied to the substrate or may be mixed with
another chemical to form a solution which is to be applied to the
substrate. As illustrated in FIG. 3, a pressure source Ps1 and a
pressure regulator Pn1 may be coupled to the supply vessel 310 via
a pressure supply line 312. Together the pressure source Ps1 and
the pressure regulator Pn1 may provide a pressurized gas, such as
Nitrogen, at a regulated pressure to the supply vessel 310 via the
pressure supply line 312. In this manner, the pressurized gas may
be used to push the liquid chemical out of the supply vessel 310
and into a supply line 314 connecting the supply vessel 310 to a
supply manifold Vd1.
[0040] A shutoff valve Sv, a pressure indicator Pd, and a
dispenser, such as syringe Sg, may be coupled to the supply line
314. The syringe Sg may have a barrel to store the liquid chemical
and a plunger to pull or push the liquid chemical into or out of
its barrel. The pressure indicator Pd may be used to monitor the
pressure within the supply line 314, and the shutoff valve Sv may
be used to provide or deny access between the supply line 314 and
the supply vessel 310.
[0041] The supply manifold Vd1 may contain a plurality of two-way
and/or multi way valves connecting the supply vessel 310 to a
plurality of mixing cells/vessels within the combinatorial
processing tool 300. Furthermore, in lieu of a single supply vessel
310, a plurality of supply vessels containing various chemicals may
be coupled to the supply manifold Vd1 such that the supply manifold
Vd1 may supply various chemicals to multiple mixing portions or
multiple site isolated reactor portions of the combinatorial
processing tool 300. Additionally, in lieu of a single supply
manifold Vd1, a plurality of supply manifolds Vd1 may be present in
the combinatorial processing tool 300. Together the plurality of
supply vessels, valves, and supply manifolds may enable the supply
of various chemicals and chemical mixtures to the mixing portion
304 and the site isolated reactor portion 306 of the combinatorial
processing tool 300.
[0042] The supply line 314 may couple the supply vessel 310 to the
supply manifold Vd1 via one or more valves within the supply
manifold Vd1. In this manner, the supply manifold Vd1 may control
the flow of chemicals from the supply vessel 310 to the mixing
portion 304 or the reactor portion 306 of the combinatorial
processing tool 300.
[0043] The output of the valve in the supply manifold Vd1 may be
coupled via a dispense path 318 to a valve Vp2. Each valve in the
supply manifold Vd1 may be coupled to a different dispense path
318. The dispense path 318 may include one of multiple lines that
may connect to the valve Vp2. Each dispense path 318 may be of a
different length or made up of different properties which may
result in different resistances in each path. The valve Vp2 may be
a multi-way valve which controls the flow of fluids/chemicals from
the supply manifold Vd1 into either the mixing portion 304,
site-isolated reactor portion 306, or both. In one implementation,
the combinatorial processing tool 300 may not have the supply
manifold Vd1 coupled to the supply vessel 310; instead, the supply
vessel 310 may be coupled directly to the dispense path 318.
[0044] The controller 316 may include a central processing unit
(CPU), a system memory and a system bus that couples various system
components including the system memory to the CPU. The system
memory may include a read only memory (ROM) and a random access
memory (RAM). A basic input/output system (BIOS) containing the
basic routines that help transfer information between elements
within the controller 316, such as during start-up, may be stored
in the ROM. A number of program modules may be stored on the ROM or
RAM, including an operating system and one or more application
programs, which may carry out the tasks described later in FIGS.
4-6. The controller 316 may be configured to send and receive
signals from other devices to perform some or all of the tasks
described herein.
[0045] The controller 316 may be coupled to certain components in
the supply portion 302 to control the calibration process, such as
the pressure regulator Pn1, pressure indicator Pd, shutoff valve
Sv, and each of the valves in the supply manifold Vd1. The
controller 316 may provide the pressure regulator Pn1 a
predetermined pressure to supply the supply vessel 310 based on an
input of a user. The pressure indicator Pd may indicate to the
controller 216 the pressure value of the supply line 314. The
controller 316 may also control the opening and closing of the each
valve, including the shutoff valve Sv and the valves within the
supply manifold Vd1.
[0046] The controller 316 may also be coupled to a motor attached
to the plunger of the syringe Sg. The controller 316 may send a
command to the motor to push or pull the plunger such that the
fluid may be provided to or drawn from the supply line 314. In one
implementation, the motor may be a step motor such that the motor
turns in equal, discrete steps, and the controller 316 may control
the direction and the number of steps in which the motor may
take.
[0047] The mixing portion 304 of the combinatorial processing tool
200 may be configured to facilitate thorough solution mixing of
chemicals provided by supply portions. In order to form a solution,
a plurality of chemicals may flow from the supply portion 302,
e.g., the supply vessel 310, into different mixing vessels in the
mixing portion 304. The mixing vessel 320 may then mix the
chemicals to form solutions. The mixing portion 304 may also
provide accurate temperature and pH control of a solution being
mixed in the mixing portion 304.
[0048] A pressure source Ps2 and a pressure regulator Pn2 may be
coupled to the mixing vessel 320 via a valve Vr and a supply line
322. Together the pressure source Ps2 and the pressure regulator
Pn2 may provide a pressurized gas, e.g., Nitrogen, at a regulated
pressure to the mixing vessel 320 via the valve Vr and the supply
line 322. An outlet of the valve Vr may be coupled to another valve
Vg to vent pressure within the supply line 322. The pressure in the
supply line 322 may be measured by a pressure transducer Pg.
[0049] The pressurized gas provided by the pressure source Ps2 and
the pressure regulator Pn2 may push the mixed chemicals in the
mixing vessel 320 through a line 324 and into the site-isolated
reactor portion 206 of the combinatorial processing tool 300. The
mixed chemicals may flow through a valve Vf1 and into a flow cell
326. The flow cell 326 may be one portion of a site isolated
reactor, and may be used to apply the mixed chemicals to a portion
or portions of a substrate under processing in the site-isolated
reactor portion 306 of the combinatorial processing tool 300. The
flow cell 326 may be one of a series of parallel cells forming
site-isolated reactors which may be configured to effect
site-isolated processing on proximate regions on the substrate.
Each of the flow cells may be configured to effect site isolated
processing, for example, by flowing fluids (e.g., mixed chemicals)
onto proximate regions on the substrate. Chemicals may be provided
to the flow cell 326 and, consequently, to a substrate via the
supply manifold Vd1.
[0050] In some implementations, different numbers of flow cells 326
may be operating simultaneously. For example, during one operation
only one flow cell may be open, while during another, eight may be
open. The variability of the number of flow cells in operation
changes the flow volume demands. Using the techniques described
herein, the pressure in the supply vessel 310 can be adjusted
during changes in the number of flow cells operating within the
combinatorial processing tool 300 to maintain fluid flow rate
calibration and consistent processing across multiple regions.
Calibration of a Chemical Dispense System
[0051] As described above, the supply portion 302 of the
combinatorial processing tool 300 may supply fluids (e.g., liquid
chemicals) to the mixing portion 304 and the reactor portion 306 of
the combinatorial processing tool 200. For example, the supply
vessel 310 may supply a fluid via the supply line 314, the supply
manifold Vd1, the dispense path 318 to the mixing portion 304 and
the reactor portion 306 of the combinatorial processing tool
300.
[0052] In combinatorial processing tools, in order to reliably and
consistently process multiple regions of a substrate, it may be
desirable to control the flow rate of the chemical liquid in a
particular dispense path 318 to the mixing portion 304 and/or the
reactor portion 306 of the combinatorial processing tool. However,
in some circumstances the flow rate of the fluid may be affected by
the various impedances of each dispense path. For example, if the
pressure applied to the supply vessel 310 by the pressure source
Ps1 is constant and only a first valve in the supply manifold Vd1
is opened to couple the supply line to a first single flow cell 326
via a first dispense path 318, the flow rate out of the supply
vessel 310 may be a first value. However, if a second valve in the
supply manifold Vd1 is opened to supply fluids from the supply
vessel 310 to a second single flow cell 326 via a second dispense
path 318, the flow rate out of the supply vessel 310 may be a
second value distinct from the first. For example, some flow paths
may have different lengths, may be made of different materials, may
include bends, etc. that may affect the total impedance of the flow
path. Additionally, if the pressure applied to the supply vessel
310 by the pressure source Ps1 is constant, the flow rate in the
supply line 314 may also change or vary based on the height of the
liquid in the supply vessel 310.
[0053] Consequently, a need exists for calibrating a flow rate with
respect to the applied pressure for each dispense path 318 in the
combinatorial processing system. Implementations described herein
provide technologies and devices for providing a specified fluid
flow rate into destination vessels (e.g., mixing vessels and/or
flow cells). According to one implementation, the specified fluid
flow rate may be obtained by providing a specified pressure to the
supply vessel containing the liquid. The pressure value required to
create the specified fluid flow rate may be determined using data
obtained from calibration data correlating the fluid flow rate and
the corresponding pressure for each dispense path 318.
[0054] FIG. 4 illustrates a method 400 for calibrating a chemical
dispense system by creating calibration data pertaining to the
fluid flow rate and its corresponding pressure for each dispense
path 318 in accordance with implementations of various techniques
described herein. Method 400 may be executed by the controller 316
illustrated in FIG. 3.
[0055] At step 410, the controller 316 may send a command to the
motor attached to the plunger of the syringe Sg to push the plunger
completely into the barrel of the syringe Sg such that all of the
fluid contained in the barrel may be removed.
[0056] At step 420, the controller 316 may close all of the valves
in the supply manifold Vd1.
[0057] At step 430, the controller 316 may open the shutoff valve
Sv to provide the syringe Sg access to the supply vessel 310 via
the supply line 314.
[0058] At step 440, the controller 316 may send a command to the
motor attached to the plunger to pull the plunger to draw the fluid
from the supply vessel 310 to the barrel of the syringe Sg. In one
implementation, the motor may pull the plunger such that the barrel
or cylinder of the syringe is completely full.
[0059] At step 450, the controller 316 may close the shutoff valve
Sv such that the supply line 314 may not have access to the supply
vessel 310. In this manner, the fluid drawn in step 440 may be
prevented from returning to the supply vessel 310. Instead, a path
may be created for the fluid to flow to the supply manifold
Vd1.
[0060] At step 460, the controller 316 may open a first valve of
the supply manifold Vd1 such that the fluid contained in the
syringe Sg may have a path to a first destination vessel via the
supply line 314, the first valve of the supply manifold Vd1, and
the first dispense path 318. In one implementation, the
combinatorial processing tool 300 may not have the supply manifold
Vd1 coupled to the supply vessel 310; instead, the supply vessel
310 may be coupled to directly to the dispense path 318.
[0061] At step 470, the controller 316 may send a command to the
motor to push the plunger of the syringe Sg at a constant velocity
or at an initial velocity with a constant acceleration depending on
the preference of the user. In one implementation, the controller
316 may store into its memory the time in which the motor started
to push the plunger and the time in which the motor completed each
motor step.
[0062] At step 480, the controller 316 may calculate the flow rate
of the fluid being provided to the destination vessel via supply
line 314 and dispense path 318. The controller 316 may use the
amount of steps that the motor has taken while pushing the plunger,
the initial time in which the motor started pushing the plunger,
and the times in which each motor step was taken to determine the
fluid flow rate. For example, each motor step may correspond to a
known volume of fluid that has been dispensed into the chemical
dispense system. The controller 316 may then determine the amount
of time that has elapsed between each motor step. Using the volume
of the fluid dispensed and the time elapsed during a motor step,
the controller 316 may determine the fluid flow rate after each
motor step. Although the controller 316 has been described to
determine the fluid flow rate based on the volume dispensed and the
time elapsed during a single motor step, it should be noted that
the volume of fluid dispensed and time elapsed may also be
determined for other motor step increments such as 1/2, 2/3, 3/4,
multiple motor steps, or the like.
[0063] Referring back to step 480, the controller 316 may also
record the pressure value from the pressure indicator Pd at the
time in which each motor step was completed.
[0064] At step 490, the controller 316 may make a correlation
between each calculated flow rate and its corresponding pressure.
For example, the correlation can be used to determine a flow rate
based on a measured pressure (see FIG. 5). In one implementation,
if the controller 316 sent a command to the motor to push the
plunger at a constant velocity, the flow rate and pressure
correlations may remain relatively the same for each motor step. If
the controller 316 sent a command to the motor to push the plunger
at an initial velocity with a constant acceleration, the flow rate
and pressure value correlation may change for each motor step, and
thus provide a wide range of calibration data pertaining to the
various pressures and corresponding flow rates of a dispense path.
The controller 316 may store the correlation into a memory as
calibration data for the first destination path 318. In one
implementation, steps 410-490 may be repeated for each destination
path 318 to create specific calibration data pertaining to each
destination path 318. The steps 410-490 may also be repeated at
different velocities for each dispense path 318.
Providing a Specific Volume to a Destination Vessel
[0065] FIG. 5 illustrates a method 500 for providing a specific
volume of a fluid to a destination vessel in a chemical dispense
system in accordance with implementations of various techniques
described herein. Method 500 may be executed by the controller 316
illustrated in FIG. 3. In performing method 500, the controller 316
may require calibration data pertaining to the fluid flow rate and
pressure correlations for each dispense path of the chemical
dispense system as recorded by method 400. For example, the method
500 can be used in implementing combinatorial processing to deliver
fluids to a reactor in a consistent, repeatable manner (e.g.,
accurate flow rate, volume, and pressure).
[0066] At step 510, the controller 316 may receive a volume of a
fluid, a target pressure, and a dispense path 318 from a user.
[0067] At step 520, the controller 316 may use the calibration data
obtained from method 400 to determine the fluid flow rate that
corresponds to the target pressure value and the specific dispense
path 318 received from the user.
[0068] At step 530, the controller 316 may calculate the time
required to provide the predetermined volume of the fluid to a
destination vessel via the specified dispense path 318 based on the
corresponding flow rate. For example, the calibration data may
indicate that dispense path `N` may have a 3 milliliter per second
fluid flow rate at the target pressure specified by the user. If
the volume specified by the user was 6 milliliters, the controller
316 may determine that 2 seconds may be required to provide the
predetermined volume of the fluid to the destination vessel via the
specified dispense path 318.
[0069] At step 540, the controller 316 may close all of the valves
at the supply manifold Vd1 and open the shutoff valve Sy.
[0070] At step 550, the controller 316 may send a command to the
pressure regulator Pn1 to regulate the pressure from the pressure
source Ps1 such that the target pressure may be applied to the
supply line 314.
[0071] At step 560, the controller 316 may open one valve of the
supply manifold Vd1 coupled to the dispense path 318 specified by
the user at step 510. In one implementation, the controller 316 may
start a timer at the instant the valve is opened to measure the
time in which the fluid may be flowing into its destination
vessel.
[0072] At step 570, the controller 316 may close the valve of the
supply manifold Vd1 coupled to the specified dispense path 318
after the calculated time to provide the predetermined volume of
the fluid to a destination vessel has expired. In one
implementation, the controller 316 may compare the calculated time
to the timer initiated when the valve may have been opened. When
the calculated time equals the time indicated on the timer, the
controller 216 may close the valve at the supply manifold Vd1.
[0073] It should be noted that correction factors may be built into
each method described in FIGS. 4-6 to account for certain sources
of errors. In one implementation, when the syringe is accelerated,
the pressure versus flow rate curve shifts. The correction factor
may be extracted, in a simple method by obtaining pressure versus
flow rate curves for different accelerations. The pressure versus
flow rate curves may be used to extrapolate to the case of zero
acceleration to obtain the true flow rate versus pressure
curve.
[0074] Although FIG. 5 illustrates a method 500 for providing a
specific volume of a fluid to a destination vessel in a chemical
dispense system, it should be noted that the method 500 may also be
used to provide a destination vessel a fluid at a specified flow
rate. In one implementation, the controller 316 may receive a
request to provide a destination vessel a fluid at a specified flow
rate via a specified dispense path.
[0075] The controller 316 may then use the calibration data
obtained from method 400 to determine the pressure value that
corresponds to the specified flow rate of the fluid and the
specific dispense path 318 received from the user (step 520).
[0076] After determining the pressure value that corresponds to the
specified flow rate of the fluid and the specific dispense path 318
received from the user, the controller 316 may then conduct steps
540-570 in the same manner as described above. However, at step
570, the controller 316 may close the valve of the supply manifold
Vd1 coupled to the specified dispense path 318 after a specified
amount of time has elapsed as opposed to a calculated amount of
time to fill a destination vessel with a specified volume.
Controlling Pressure with a Dispenser
[0077] FIG. 6 illustrates a method 600 for controlling the pressure
of the fluid in the supply line 314 with the syringe Sg in a
chemical dispense system in accordance with implementations of
various techniques described herein. Method 600 may be executed by
the controller 316 illustrated in FIG. 3. The method 600 in one
embodiment is a feedback system that measures a pressure in a flow
line and adjusts the flow rate (by adjusting, e.g., the velocity of
the syringe plunger) to achieve a desired pressure of fluid
delivery into a flow cell.
[0078] At step 610, the controller 316 may receive a target
pressure from a user such that a fluid may be delivered into the
supply line 314. In one implementation, the controller 316 may open
one valve of the supply manifold Vd1 and close the shutoff valve Sv
such that the syringe Sg may be coupled to a destination vessel via
a destination path 318.
[0079] At step 620, the controller 316 may send a command to the
motor attached to the plunger of the syringe Sg containing the
fluid to push the plunger at an initial velocity.
[0080] At step 630, the controller 316 may receive a pressure value
from the pressure indicator Pd.
[0081] At step 640, the controller 316 may compare the received
pressure value with the target pressure value received by the
controller at step 610.
[0082] At step 650, the controller 316 may adjust the velocity at
which the controller 216 is pushing the plunger of the syringe Sg
such that the pressure on the supply line changes to match the
target pressure. In one implementation, if the measured pressure
value is less than the target pressure, the controller 316 may send
a signal to the motor coupled to the plunger of the syringe Sg to
increase the velocity in which the motor is pushing the plunger.
Conversely, if the measured pressure value is greater than the
target pressure, the controller 316 may send a signal to the motor
coupled to the plunger of the syringe Sg to decrease the velocity
in which the motor is pushing the plunger.
[0083] At step 660, the controller 316 may maintain the velocity at
which it pushes the plunger of the syringe Sg after determining the
velocity that corresponds to the target pressure.
[0084] While the foregoing is directed to implementations of
various technologies described herein, other and further
implementations may be devised without departing from the basic
scope thereof, which may be determined by the claims that follow.
Although the subject matter has been described in language specific
to structural features and/or methodological acts, it is to be
understood that the subject matter defined in the appended claims
is not necessarily limited to the specific features or acts
described above. Rather, the specific features and acts described
above are disclosed as example forms of implementing the
claims.
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